US2541237A - Hydrogenolysis process for the production of gasoline and a gas oil from residual oils - Google Patents

Description

l L. B. GooDsoN 2,541,237 HYDROGENOLYSIS PROCESS FOR THE PRODUCTION OF GASOLINE AND A GAS -OIL FROM RESIDUAL OILS Feb.13,1951

RESIDUE F/GURE /v Feb. 13, 1951 L. B. GooDsoN HYDROGENOLYSIS PROCESS FOR THE PRODUCTION OF GASOLINF ANO A GAS OIL FROM RESFOUAL OILS 2 Sheets-Sheet 2 Filed Dec. 2, 1947 9 m 2 L O 6 w l l 3 3 m 3 .H ZD D AI fmmoum Iv ZmOOw-DL 4 w 4 w lv lo :I IV G .NL ZmUOmD I ImmnmDJm mJU Um N s U m 3 N E 0 OR E S 3 O D C GSA CV. A OUG H I` RL maw N H m m E L zmoomnr G l O mmm- 10 .m .r U .PUDOONE m OMFDJE R M All D Y. 2 H d l 2 H E J S 3 3 6 E 2 R E E F C W. A| .d

FEED

RECYCLE RESIDUE FROM FRACTIONATORv F/GURE 2 ATToR/VEKS Patented Feb. 13, 1951 UNITED .STATES .A'rizlsrr orsi-CE l.Luke-B.-Groo'ds|tnn, Bartlesville, Okla., assignor'to :Phillips-Petroleum Company, a ccrporationof Delaware Application December 2, 1947, Serial No.' 789,223

4.Claims. l This inventioni relates to 'an' improved process of hydrcgenolysis. In @one of its amore specic aspects it relates toa novel manner of introducing hydrogen to a hydrogenolysis process.

The term hydrogenolys-sfas used in this'invention, means destructive :hydrogenaticn ivvherein Acracking and hydrogenationfreactionsiare taking place simultaneously; .Hydrogeno'lysis, yas fdistinguished fromlhy'drogenation'.wherein the sim- 'ple addition ofhydrogen to 'unsaturated 'bonds takes place, is cracking under hydrogenating vconditions so that" the :products .of 'the cracking reaction are substantially Imore saturated than when hydrogen or lmaterials supplying hydrogen are not present.

Hydrogenolysis processesare most commonly employed on coals andheavy residual or distillate oils for the production of substantialyields -of low-boiling vsaturated 'products such vas gasoline, intermediatedistillateslwhich may be utilized as domestic fuels and, tosomev extent, `still `ated on a-strictly thermalbasis or inthe presence of catalysts.

The art discloses processes for the hydrogenolysis of residual oils in which hydrogen isintroduced at one or morepoints in a catalyst chamber. In all of'these processes stress `is laidon the use of high purity' hydrogen. "My invention makes 'directuse of by-product-hydrogen With- 'outpurication `In addition, most of the processes vutilize 'concurrenthor countercurrent :contacting. 'One embodiment of myv'invention uses both concurrent andcountercurrent flow' inthe same chamber, Autilizing the 'bestaspects' of each `to produce a' better quality gasoline'without imparing the properties of the by-productgasoil. This is accomplished by using diierent catalyst zones and controlling' the pai'tial'pressure on'con- -centration of hydrogen in 'said zones more or less independently of each other.

An object'ofthe present invention isa novel and improvedfmethod of 'hydrogenolysis Another object is the manufacture of ahighquality gasoline.

Another obj ect is the production of -a highquality gasolinaandf-a good quality gasoil and a parailinic typeresid-ue in a single hydrogenolysis step.

'Another object is'k the catalytichydrogenelysis 'of r1a total feedstock withcatalytictreiormingtof the gasoline range hydrocarbons.

Another object iis x the :eITective '.fseparation by gravity. and: `oy-.stripping of A:theliquid :and vapor portions of theireactorefiluent Within therreactor.

Anotherv objectI is to :contact lcountercurrently and 4concurrently `a `material' to'be treated with hydrogen in' acne step :process of hydrogenolysis.

A further 'obj ect :is itorpreheat` the hydrogen to `be introduced to the-reaction rchamberrof a` hydrogenolysis process to i Vreaction temperature,l thus aiding inthe maintenance of thercontactchamber at reactionv temperature.

Another 'object isto reduce the volume-'ot hydrogen required 'Without .reducing the -yield of gasoline.

Other objects-and advantages 'of this invention will 'become apparent from"the accompanying disclosure and discussion.

In accordance With va 4.preferred sembodiment o'f this invention, `a-rerlnery residual oil such-asi reduced topped crude, 'fuel oil, tar,- etc.,`A isu passed "through heating :equipment and yintroduced at theA top of arstcatalystzone,=and='relatively `pure hot hydrogen is introducedA at the bottom of'said :first catalyst zone, contactingthe oil chargecountercurrently under 'conditions 'of ydestructive hydrogenation. Thus'the residual oil' is'treated in la rst catalyst zone, :and -iarsaturated'lparafnic gas oil recovered'through 1an outlet near thebottom of the zone. Because ofthe .purity .of'theihydrogen in this catalyst -zone' thengas oili'recovered Ais saturatedwhich is ay vdesired property. The Alight ends and gasolinefraction are passed'to a :sec- 0nd catalyst zone'wherethey are-contacted concurrently With diluted hydrogen, erg. nbr-product hydrogen, under vreform-ing 'conditions Due rto the diluted condition of the hydrogen fin the second catalystzone the veloctyfory the cracking reaction exceeds that yof the hydrogenation 'reaction,'however,1.at the same time,.sucient hydrogen is present'to preventicoking. .By controlling the dilution of the hydrogenfany combination of saturated and unsaturated 'compounds may be produced. 'The same or `.different kcatalysts may be used in the different zonesasrdesre'd.

In a second embodiment of this invention, a re'nery residual oil ispassedfthrough 'heating equipment'and introducedk at'the top of-ia'catalyst zone where it is contacted `countercurrently under destructive' hydrogenation conditions, :irstwith relatively pure hydrogen, producing saturated compounds, and vsecond `with diluted hydrogen, producing unsaturated compounds. As'inthe rst embodimentfby vcontrolling'the dilution of the hydrogen '.anyfccmbination of saturated land unsaturated compounds may be produced. In addition'the process describediinthis invention, reducesthe volume of .hydrogen required, making for economy, and utilizes by-product hydrogen without purification.

A more clear understanding of some of the many aspects of this invention may be had by referring to the attached schematic ow diagrams.

As shown in Figure 1, the renery residual oil is introduced to the lower portion of catalyst chamber I0, through line II, heat exchanger I2, and heater I3 at a temperature between 850 to 950 F. Fresh hydrogen, plus recycle hydrogen of 95-98 per cent or better purity, is introduced at the bottom of catalyst chamber I through lines I4 and I6, heat exchanger I'I, line I8, and heater I9. Dilute by-product hydrogen is introduced to catalyst chamber I0 slightly below the upper portion of the catalyst bed, but above the point of introduction of the fuel oil charge, through line 2|, and heater 22. In this manner, the top nortion of the catalyst bed is contacted with dilute hydrogen alone. 'I'he gasoline and light ends formed in the lower portion of the catalyst chamber are stripped up through the top portion of the catalyst bed where they are reformed in the 'presence of dilute hydrogen. These reformed materials are then removed from catalvst chamber III, through line 23, heat exchanger I?, and line I5, to cooler 24. The gas oil and heavier materials produced in the lower portion of the catalyst bed are removed from catalyst chamber I0 through an outlet near the bottom of the chamber through line 25, heat exchanger I2. and line I5, to cooler 24. From cooler 24 the products of the process are passed through .line 2l to high pressure separator 28. In high pressure separator 28, hydrogen and light gases are separated and passed through line 29 to hydrogen recovery unit 3| where hydrogen of 95 to 98 per cent purity is separated for recycle. The residue materials from high pressure separator 28 and hydrogen recovery unit 3| are passed through lines 32 and 33 respectively, and line 34 to low pressure separator 36. In low pressure separator 36, vent gases are separated and removed through line 3l, and the residue is passed through line 38 to fractionator 39. In fractionator 39, a light gas fraction is separated and removed through line 4 I, a gasoline fraction is separated and removed through line 45, a gas oil fraction is separated and removed through line 42, a recycle fraction is removed through line 44, and a residue is removed through line 43 for recycle through line 44 to catalyst chamber I0 and/or recovered as a by-product of the process.

In some cases it may be desirable and advantageous to carry out the recovery and fractionation of the gasoline and light ends in equipment separate from that used for the heavier oils, thereby making possible more eicient fractionation than is possible in those processes where the entire catalyst chamber efliuent is charged to one fractionating tower. Therefore, if desired, the gasoline and light ends removed from the top of catalyst chamber I0, through line 23, and heat exchanger I?, may be taken through a line, other than line I5, to a separatory and hydrogen recovery system, and a fractionation system,v separate from that used for the heavier oils taken from the bottom of said catalyst chamber I0 through line 25. This additional recovery apparatus is omitted from the schematic drawing given in Figure 1 for the sake of clarity and simplicity.

General operating conditions are as follows: The temperature of the lower portion of the cata- ,4 4. lyst chamber is maintained within the range of 850 to 950 F. and in the upper portion of the catalyst chamber at 950 to 1050" F. The pressure within the catalyst chamber should be maintained within the range of 3000 to 5000 pounds per square inch gauge. The velocity of the per cent, or better, hydrogen through the catalyst voids should be in the range of 0.1 to 0.25 foot per second. The oil charge rate should be maintained at 0.5 to 2.0 volumes of oil per volume of catalyst per hour. The concentration of the diluted hydrogen introduced just below the upper portion of the catalvst bed should be in the range of 10 to '.75 per cent hydrogen. These operating conditions may necessarily be changed, depending on the feed stock to be treated, and the desired properties of the product gasoline and byproduct gas oil.

In a second embodiment, as shown in Figure 2, a residual oil is introduced at the top of catalyst chamber I0', through line II, heat exchanger I2, and heater I3 at a temperature in the range of 800 to 975 F. and a pressure in the range of 3000 to 5000 pounds per square inch gauge. Diluted hydrogen is introduced at the bottom of catalyst chamber I0 through line 2| and heater 22. Recycled hydrogen and fresh hydrogen are introduced to catalyst chamber I0 between onehalf and one-quarter, but preferably at one-third, of the total length of the catalyst bed from the bottom through lines I4 and I5, heat exchanger Il, line I8, and heater I9. If desired, a portion of the recycled hydrogen may be introduced to catalyst chamber I0 through lines I6 and 2),v

and header apparatus 30 to act as a temperature control. The oil to be treated is contacted countercurrently, first with relatively pure hydrogen, and then with diluted by-product hydrogen. rihe treated oil is removed from catalyst chamber I0 through line 26, heat exchanger I2, and line I 5 to cooler 24 (not shown). The hydrogen and light gases are removed from the top of catalyst chamber I0 through line 23, heat exchanger Il, and line I5 to cooler 24 (not shown). From cooler 24 the materials are treated as described in the first embodiment shown in Figure 1.

The lower portion of the catalyst bed is contacted with diluted hydrogen only, thus making the cracking reaction velocity exceed that of the hydrogenation reaction. The hydrogen concentration in the lower portion of the catalyst bed is reduced to about one-half or one-fourth that in the upper portion of the bed so that there is not sufficient hydrogen present to allow the hydrogenation reaction to go to completion. However, there is sufcient hydrogen present to prevent the formation of coke which usually accompanies cracking reactions.

General operating conditions are as follows: Temperature of the catalyst chamber should be maintained within the range of 800 to 975 F. The pressure within the catalyst chamber should be maintained within the range of 3000 to 5000 pounds per square inch gauge. The velocity of the hydrogen throughout the catalyst voids should -be in the range of about 0.1 foot per second. The oil charge rate should be maintained at 0.5 to 2.0 volumes of oil per volume of catalyst per hour. The diluted hydrogen which is introduced at the bottom of the catalyst chamber should be in the range of 10 to 75 per cent hydrogen.

Various valves, pumps, and other conventional equipment necessary for the successful practice in "the fart zand have obeen "'omittedrom f these v:schematic-"drawings for-"lthe'fsake fof clarity.

'AmexampleiofJthisinventionlusing 'thezequipfmentdescrlibed. 'in Figurejl"V isha-follows:

. tFresh redu cedftopped crudezat"` 2415API1 gravity, and r albo'ilingr `range-ict. 185022120 over i000 v.is charged Y:atn'the :1 topfof `rthel .lower sectionwof f. the Acatalyst bedfwhichiconsists of 14' percent zmolyb- 'denum disulfide on v .1/8" fx 'L1/ upellets .off alumina .g'el. The lowerzsectionofsthecatalystzbedzoczcupieslabout =60:perfcent;of' the catalystchamber. '.The `charge :stock :is 'preheated byxa heat v'rexichangerzan'dl a'heaten and :introducedto the acat- #.alystl chamberatSO". and at a :pressure off3500 'pounds' per :squareiinch-fgauge. Hydrogen of f r95 per cent 'purity f consisting :.fof i fresh :and recycle .hydrogen fistupreheated fat880. .F.randintroduced `:at the :bottom :ofthe catalyst fchamber. The hy- .Sdrogenfiand zcharge'sto'ck. are` :contactedl countercurrently in the molybdenum disulfide-:portion of theffcatalystubed, .where hydrogenolysis takes place. The gas oil and heavier materials pass downward andare completely Ahydrogenated by .the .high;.-purity.hydrogen.-introduced-fat'the -bottom of the chamber.

The light material .and gasolinestock produced by the hydrogenolysis process' in the lower portionrcfg the chamber are stripped by the'now of hydrogen ilupward `lto the fraupper `section -of tithe vcatalystbed consisting of @per cent molybdenum dioxide on y1/8-x pellets of# alumina gel. This lportion offthe-catalyst bedfoccupies about 40'per 'cent of thecatalyst chamber. 'Hot 2513er ycent hydrogen and '75 per cent inert gas preheated to a temperature of 1100 F. and at a pressure of 3500 pounds per square inch gauge is introduced to the catalyst chamber, just below the upper portion of the catalyst bed, but above the point of introduction of the fresh oil charge, and contacted concurrently with the gasoline and light gases. This upper portion of the catalyst bed is maintained at 975 F. The light materials are reformed in the presence of the diluted hydrogen. Because of the diluted state of the hydrogen the hydrogenation of these light materials and gasoline does not go to completion, leaving a portion of unsaturated compounds valued in motor fuel. At the same time, however, enough hydrogen is present to prevent coking which normally accompanies cracking reactions.

The gasoline and light ends are taken oir the top of the catalyst chamber and combined with the gas oil and heavier materials which are taken oif at the bottom of the chamber. This mixture is cooled and passed to a separator where the hydrogen is removed for recycle. The remaining materials are separated and fractionated, recovering the gasoline fraction as a product of the process and the gas oil as a by-product of the process. The volume per hour of the charge stock used, having an API gravity of 24 and a boiling range of 850 vto 1000+ F., is 1.5 volumes per volume of catalyst per hour. The velocity of the 95 per cent purity hydrogen introduced at the bottom of the catalyst bed is 0.2 linear foot per second through the catalyst voids which amounts to 6000 cubic feet per barrel of charge "The 400Y F. 'endpoint-1gasolinerecovered-zasaa product -of the processfconsistsfof :30.3 liquid volume `percent of thecharge' stock` andhas an API gravity' off58I `and-an A S'I'lVL .Gclearl octane number of 62.3. The -hydrogen vconsumption .during the operation' :is :between 1200;'and-22500 tcubic feet r per barrel and .'averlaged about 1550 fcubic feet per lbarrel.

The Vproperties iof they .gasoline produced .may be varied .within wide limitseby `.controlling the concentration `of the. hydrogen Yinthe upper catalyst zone. Fcr`example,"more 'hydrogen would produce a gasclinezfwithvmore:saturated compon- `'entswhile :less hydrogen -wouldiprovide more unsaturated compounds. Another advantage :fis ythe lreduction in'fvolume of' hydrogen .consumed Eand the V.use lof Aby'-Lproduct.:hydrogen which needs Ino :purification Although the process has been described: and vexenfnliied in terms-1:01? its :preferred yunodications; it -is .understoodflthat' various changes l.may fbe made without departing' from the'fspirit; of ythe process'asdisclosed or from vthescopecf the Yclaims.

I claim:

'1. A'process -fcr catalytic Mhydrogenolysis :of reineryresidual oils `which Iccmprises contacting a refinery residual `roilecuntereurrently ina .n1-st Vcatalyst zone over afsuitable' hydrcgenolysisicata- 'lyst with hydrogen of Aat least 95-'per cent purity, said contacting -taking VVAAplace at a temperature between-850l and 950 1F. f and a 2pressure between 3000-'and 5000 pcs. i.-'g.,-separating the gasoline and light hydrocarbons from the gas oil and heavier material by means of gravity and stripping, passing said gasoline and light hydrocarbons to a second catalyst zone, contacting said light hydrocarbons and gasoline concurrently with diluted ley-product hydrogen of between l0 and '75 per cent purity introduced at a lower end of the second catalyst Zone over a suitable hydrogenolysis catalyst, and thereby reforming and partially hydrogenating said light hydrocarbons and gasoline at a temperature between 950 and 1050 F., recovering said reformed materials from the top of said second catalyst zone, completely saturating said gas oil and heavier materials in said rst catalyst zone with the high purity hydrogen, recovering said saturated materials from the bottom of said rst catalyst zone, combining said light hydrocarbons and gasoline and said saturated gas oil and heavier materials, cooling said mixture, separating the excess hydrogen for recycle, separating vent gases from said mixture, and recovering by fractionation an improved gasoline containing unsaturated components as a product of the process and a, good grade saturated gas oil as a icy-product of the process.

2. The process according to claim 1 in which molybdenum disulfide is used as the catalyst in said first catalyst zone, and molybdenum dioxide as the catalyst in said second catalyst zone.

3. A process for catalytic hydrogenolysis of refinery residual oils Which comprises contacting a renery residual oil countercurrently in a rst catalyst zone over a suitable hydrogenolysis catalyst with hydrogen of at least per cent purity, said contacting taking place at a temperature between 850 and 950 F. and a pressure between 3000 and 5000 p. s. i. g., separating the gasoline and light hydrocarbons from the gas oil and heavier material by means of gravity and stripping, passing Said gasoline and light hydrocarbons to a second catalyst zone, contacting said light hydrocarbons and gasoline concurrently with diluted by-product hydrogen of between 10 and 75 per cent purity introduced at a lower end of the second catalyst Zone over a suitable hydrogenolysis catalyst, and thereby reforming and partially hydrogenating said light hydrocarbons and gasoline at a temperature between 950 and 1050 F., recovering said reformed materials from the top of said second catalyst zone, completely saturating said gas oil and heavier materials in said first catalyst zone with the high purity hydrogen, recovering said saturated materials from the bottom of said rst catalyst zone, fractionating separately material recovered from the top of said second catalyst Zone thereby recovering an improved gasoline, and fractionating separately material recovered from the bottom of said rst catalyst zone thereby recovering a good grade gas oil as a by-product or" the process.

4. A process of manufacturing an improved gasoline and a good grade gas oil from refinery residual oils by catalytic hydrogenolysis, which comprises introducing a refinery residual oil at a temperature n the range of 850 to 950 F. and a pressure in the range of 3000 to 5000 p. s. i. g. to the top of a bed of suitable hydrogenolysis catalyst in the lower portion of a catalyst chamber at a rate of 0.5 to 2 liquid volumes per volume of catalyst per hour, contacting said oil with hot hydrogen of relatively high purity introduced at the bottom of said catalyst chamber at a rate through the catalyst voids in the range of 0.1 to 0.25 foot per second, cracking and hydrogenatgenating the hydrocarbons boiling in and below ing'said oil as it passes downwardly through said catalyst bed and sweeping thelighter hydrocarbons boiling in and below the gasoline range produced thereby upwardly through said catalyst by means of said hydrogen, contacting said lighter hydrocarbons with a second bedof hydrogenolysis catalyst placed above the first bed thereof and within the same chamber such that there is free communication between the two beds Yof catalyst, reforming and partially hydro- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,955,297 Jennings Apr. 17, 1934 1,962,792 Van Voorhees et al. June 12, 1934 2,321,841 Mekler et al. June 15, 1943 2,335,610 Plummer Nov. 30, 1943 2,374,095 Helmers Apr, '17., 1945

Claims (1)

1. A PROCESS FOR CATALYTIC HYDROGENOLYSIS OF REFINERY RESIDUAL OILS WHICH COMPRISES CONTACTING A REFINERY RESIDUAL OIL COUNTERCURRENTLY IN A FIRST CATALYST ZONE OVER A SUITABLE HYDROGENOLYSIS CATALYST WITH HYDROGEN OF AT LEAST 95 PER CENT PURITY, SAID CONTACTING TAKING PLACE AT A TEMPERATURE BETWEEN 850 AND 950* F. AND A PRESSURE BETWEEN 3000 AND 5000 P. S. I. G., SEPARATING THE GASOLINE AND LIGHT HYDROCARBONS FROM THE GAS OIL AND HEAVIER MATERIAL BY MEANS OF GRAVITY AND STRIPPING, PASSING SAID GASOLINE AND LIGHT HYDROCARBONS TO A SECOND CATALYST ZONE, CONTACTING SAID LIGHT HYDROCARBONS AND GASOLINE CONCURRENTLY WITH DILUTED BY-PRODUCT HYDROGEN OF BETWEEN 10 AND 75 PER CENT PURITY INTRODUCED AT A LOWER END OF THE SECOND CATALYST ZONE OVER A SUITABLE HYDROGENOLYSIS CATALYST, AND THEREBY REFORMING AND PARTIALLY HYDROGENATING SAID LIGHT HYDROCARBONS AND GASOLINE AT A TEMPERATURE BETWEEN 950 AND 1050* F. RECOVERING SAID REFORMED MATERIALS FROM

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